The Nasu Files
by Jouaint
Summary: Two universes have always stood closely next to on another, being so close one need not posses the Kaleidoscope to travel between them. One of Merlin's less well known abilities is his ability to see in to the future so what if on day two different versions of him have a vision and erect a barrier between the two worlds. It stood for nearly 2,000... see rest of summary inside.
1. Chapter 1

**Dresden Files/ Nasuverse crossover challenge**

Two universes have always stood closely next to on another, being so close one need not posses the Kaleidoscope to travel between them. One of Merlin's less well known abilities is his ability to see in to the future so what if on day two different versions of him have a vision and erect a barrier between the two worlds. It stood for nearly 2,000 years but it too has an end. With the defeat of the Crimson Moon the barrier was weakened but not destroyed. But the barrier was finally destroyed with the near simultaneous destruction of the corrupted grail by Saber in the Fourth Holy Grail War and the aborted Darkhallow. Now the worlds are in connection again and unlike before people are realizing it. How will two worlds react when they find themselves existing side by side and how both have their own secret worlds hidden inside.

This is a Dresden Files and Nausverse Challenge. Rules are simply to follow the above premise.


	2. Prologue

**I do not own the Dresden Files or the Nasuverse**

_My first actual story so bear with me._

**Prologue**

Two men stand across from each other, one appeared old yet filled with vitality and the other young yet carrying a weight of many long years, utterly alone, they are only a few feet of distance between them and yet there are more miles between them than any one universe could possibly have. Both are wizards, though for different rules. If one looks closely one can tell that they both look similar to each other almost as if one is looking at a mirror, but even though they look so similar there is something that tells an observer that these two are not mere twins but something much more. They are famous and easily some of the greatest and most powerful beings humanity has ever produced (even though both are but half-human) and quite possibly the best magic users humanity has or will ever have. Their name is Merlin Ambrosius.

The older looking one says, speaking to no one in particular, "This will be the most difficult thing I have ever done, even more than that prison I built". The other picking up on the same line of thought agreed saying, "Aye, Caliburn is nothing compared to this".

The elder looking across to his younger-appearing counterpart said, "I wonder still if we should do this", he and his counterpart starting there long, delicate, and energy intensive work, "play God in such a manner". The younger one replied, "You know as well as I that we must do this we have both seen what will come to be if we do nothing".

"I know, but still to separate the worlds…"

"They are already separate the only reason we know is because of my forays into the Kaleidoscope. The only other beings that are aware are a handful of the Gods (almost entirely composed of the ones famous for knowing the deep secrets of the world), the Faerie Mothers and _maybe_ a few of the other fae, the Angels, Gaia, and Alaya. Right now no one else is aware and we need to keep it that way: The Gods who are ware aren't the type to interfere in a truly detrimental manner, Faerie Mothers and the Fae as extensions of Gaia won't do anything that would endanger all life on the planet, Alaya will always try to preserve Humanity and the Angels are so wrapped up in their rules that they won't do anything to disastrous. Even excluding the danger we have both foreseen the same cannot be said about the others: the Types, especially the Crimson Moon, could attack any time once they realize the danger posed by Gaia and Alaya, and the Outsiders would pour into reality and destroy all."

"You are right", the elder one conceded. He has started to literally glow as he carved symbols of power into the very fabric of reality. "I am glad you have seen reason", the younger one replied surrounded by a Kaleidoscope of colors as he reached back onto the very Root of Existence to affect the change he desires.

A minute later he says, "Dammit this would be easier if had actually managed to complete one of these True Magics". The elder one replied, "Yes you never did manage to finish those did you, though didn't you say taught as much as you could to your apprentices, and for that many how many did you manage to start?"

"Aye, I started five, Five True Magics, and I taught the Heavens Feel to that brat Eizenburg or something. I also taught the Kaleidoscope to my lazy-ass student Kishur. It's a shame he is the way he is he could probably complete it if he actually put up the effort either way I told him to look after our work after were finished since the Kaleidoscope is soon going to be the only way for one to go in between our two worlds."

The elder one, nearing the climax of his power and work, said, "Okay I am nearly done spreading out the NeverNever and using it plug up the Ways that link the two worlds. It will probably drastically increase the power and influence of the Faeries but that should help mitigate the effect of your part of the plan." The younger one, his mission almost complete as well, replied, "And I will create a temporary temporal anomaly and while Gaia and Alaya are both focused over here and leave only the bare minimum of the their consciousness on your side and I will use the newly empowered NeverNever to force as many of the Gods and Phantasmal Beings as I can over into your world, while laying down the foundations for it to be done automatically."

The Elder one noted that, "You know there will be consequences with Alaya and Gaia's reduced presence humanity will inevitably grow weaker and much of the subtleties and depth and (some if comparatively small amount) power of magic will be lost to everyone, not just humans, on my side, at best vaguely remembered but unable to accomplish it, at worst completely erased from mind and memory and without those two fundamental bases magic w. Magic will be brutalized and I have no doubt there will be consequences on how certain magics interact with the human soul. Your world will face similar crises (if for different reasons). Gaia and Alaya will no doubt be alternating between being panicked and being pissed. Gaia and Alaya will no doubt both apply pressure on humanity and everything in general; greatly weakening humanity and your magic will probably go through the opposite of what ours went through. I fear the damage we will do today can never be undone." The younger one affirmed him saying, "Only if we succeed. If your barrier were to ever fall no doubt many if not all of the restrictions would fade or possibly disappear completely."

After they had all but finished their work the younger one, looking utterly exhausted, asked the elder, "Hey old man, we are not going to survive this are we?" The Elder replied, "Old Man aren't you three centuries older than me? But anyways I guess the best way to put it would be no. There isn't a chance in hell where surviving this."

There work complete and a bright light surrounding them destroying their bodies, but sparing their souls, the younger one said one last thing, "Heh, well at least I'll get to see what's happening with Arturia."

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**A****gain this is my first real story (or chapter for that matter) and I (currently) have no beta reader so please go easy on me. **

**Any reviews are welcome, though I ask that any flamers at least keep the obscenities down to a minimum.**


	3. Chapter 1: Hell's Bells

**I do not own the Dresden Files or the Nasuverse**

_My first actual story so bear with me._

**Chapter 1 Hell's Bells**

Inside a once formerly grand theater room laid a cup or rather a grail, the 767th Holy Grail. But this grail was not in any way holy for inside lay a thing of utter malice and darkness something that could only be described as **A LL THAT WHICH IS EVIL, **it was at once a curse and a wish, a concept and a living thing, it was Angra Mainyu Persian God of Darkness and evil. Because that which lay in the grail had not always been there but rather had come to corrupt and taint it utterly.

During the previous Grail war the, 3rd Holy Grail war, the Grail was utterly corrupted when the Eizenbern, one of the three families who founded the Holy Grail War alongside the Wizard Marshall Zelretch, tried to cheat and summon a god. They both succeeded and failed for while the being they summoned was indeed a Divine Spirit it was before that a Heroic Spirit and the servant container, which could not hope to contain the full might of a Heroic Spirit could not even begin to contain a Divine Spirit. Said servant lost fairly quickly but in losing achieved something he did not imagine he became integrated with the Holy Grail's most basic system, the Greater Grail, which unlike his measly servant container (which could not even fully express the abilities he or any servant had when they were alive) could bear his full might.

Unfortunately for him that same thing also prevented him from escaping because while he was at full strength the grail was powerful enough to keep him from escaping. So trapped he realized his only way out was for someone to use the Grail on a significant enough wish that would allow him to brute force his way out onto the world in order to accomplish his goal.

So we come to the Fourth Holy Grail War were there was a man with such a wish a wish to end all war and conflict. When this man known as Kiritsugu Emiya was confronted by Angra Mainyu he rejected it and fled to its center so as to destroy it.

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Two beings enter into the room both are servants one is a male Archer, also known as Gilgamesh the King of Heroes, and the second is a female Saber, also known as Arutria Pendragon . King Arthur the King of Knights. Both desire the Grail if for different reasons and both are unaware of the truth about the grail. Saber enters through a hole in the wall and as she moves to approach the grail she hears one voice (a voice she has come to loath) say something the absolutely horrifies her.

"Saber by the power of my Command Seal I order you, use all your power to destroy the grail," commands Emiya Kiritsugu and again he says, "Saber by the power of my final command seal I order you, Annihilate the Grail."

"NOOOOOOO…" She hears someone scream before realizing it is she and at that moment she unleashes Excalibur one of the greatest holy weapons that's purity and power reaches unto the level of the Three Swords of the Cross and the blades of the Archangels. Its power unleashed it is a weapon that even **ALL THAT WHICH IS EVIL **would tremble before. Blasting through the Grail this colossal power collides with another and then something else happens for any another place and another time something similar happens.

But Kiritsugu is tossed from the building and the last thing he hears is tremendous crash like some great wall had been suddenly torn down.

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Hello my name is Harry Dresden and I am about to do something that is insanely and suicidally stupid. I am about to interrupt some necromancers who are in the process of completing a spell that will basically allow them to ascend into godhood.

Now interrupting any spell can be a dangerous thing, normally just for the wizard himself, but depending on the type of spell and the circumstances the casualties can get pretty extensive still I am pretty sure I won't have to worry about anyone outside of this park and inside well hopefully Butter was smart enough to run like hell away and the rest are just me, some Wardens and the aforementioned Necromancers.

So then as I run up to the center of the circle and slam my blasting rod right into the middle and pump as much magic as I can while shouting, "PYROFUEGO", I am only barely able to hear someone shout, "You fool you'll kill us all!"

Immediately after that three things happen:

The spell fails.

A giant explosion happens and throws me backwards.

And finally I hear a sound like something breaking.

The last thing I think as my vision is consumed by blackness is, "I really hope I didn't just break the universe."

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Kirei Kotomine wakes up. After realizing that he is, somehow, still alive he looks around and realizes he is surrounded by rubble and a hateful burning fire. "No", he whispers to himself, "Rather a curse in the form of a fire."

Extracting himself from the rubble he goes looking and discovers his former master's and now his servant Gilgamesh sitting on top of some rubble.

"Ah, Kirei it is good to see you", says the King of Heroes. Kotomine a little put off by the Heroic Spirits unusual behavior asks, "If I may be so bold, what has caught your eye oh King."

"Oh, Kirei can't you feel it? The world is even now changing around us. Gaia is spreading out her power and greatly lessening her effect on magic in general. Both beings and spells are more powerful and longer lasting than before and it is not done yet this will only continue. Beyond that Alaya is releasing its grip on humanity. Soon all those mongrels will be far more powerful, if not as powerful as humanity was in my day. Do you not see Kotomine what you call the Age of the Gods shall soon be upon us again.

"New so-called heroes shall appear and old threats shall be revived. But beyond that my kingdom is at last whole once again."

"Whole what do you mean by that, the world is still divided between the various nations", asked Kotomine.

"Ah, Kirei still you do not understand, but since you have been such a worthy servant I shall tell you. This world and another lay side by side or rather this universe and another are so close that they touch. Now do to the unique nature of this one does not need to possess the Magic you call the Kaleidoscope to travel between the two. All one needed was the proper knowledge and magical ability. Honestly it might be possible to do so now with modern technology, on a practical level, just as we did so with magecraft during my time, and that's excluding the natural Ways that exist anyways. Now Gaia and Alaya exist in both universes but they are the same Gaia and the same Alaya. Too put it another way well you are an expert in healing so you can compare the two worlds to hemispheres of a brain ours being the Left and theirs is the Right, two distinct and vital parts but one true whole. And who should rule over all of Gaia and Alaya, but I Gilgamesh the King of Heroes?"

"I se.." Kotomine starts before he hears some rubble moving and notices Emiya Kiritsugu madly searching through the rubble trying to find someone anyone. Kotomine starts to move to kill him, but stops and leaves Kiritsugu to his task.

"Oh? I had not expected you to just let him go so easy Kotomine." Gilgamesh amusedly states. "But at any rate it does suit my purposes we must set up and get ready I believe the world will get very interesting soon." saying that Gilgamesh summoned a magnificent Golden flying ship, Viamanna. "But how Berserker destroyed it?" Kotomine Kirei asked as they boarded the magnificent aircraft. Gilgamesh turned back and smirking said, "Oh Kirei you haven't seen anything yet."

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The man known as Kiritsugu Emiya has finally saved someone. Having desperately searched through the ruins caused by him to prevent the release of a greater horror he found one person who had managed to hold on despite all the odds a young boy with red hair. Having found this one person he quickly extracts and implants Avalon into him. Noticing that the boy has lost consciousness he goes to pick him up and carry him out of this fiery hell when he feels a blade pressed against his neck. Slowly turning around he sees the face of his former servant glaring down at him.

"Why, why should I not kill you now? Why did you betray me? Why did you take the grail from me?" Arturia Pendragon the King of Knights demands.

"Because the grail was horribly and irreversibly cursed." Explained Kiritsugu.

"Dammit and Damn you, but I believe you," accepted Arturia as she slowly lowered her sword. "I see you have implanted Avalon into this boy. Don't look surprised I am much more than I was as a servant." She says as she bends down and allows some of her Prana to fill Avalon to capacity. "There that should be enough to allow him to recover. He can keep the original though I do not need it and I believe I can sense something of a destiny about this boy.

"Now than I do want to know why you are so badly cursed?" Arturia inquired.

"How do you know I was cursed?" Inquired Kiritsugu.

"There you go again underestimating me. Though you probably don't know this I am actually a quite capable magic user. Though I have always personally disliked using it beyond my Prana burst, during my life Merlin did insist on teaching me as much as he could and I was one of the few people with more Prana that even him. While my practical abilities did suffer, due to a lack of practice and interest, my theoretical knowledge was second only to Merlin and Morgana."

"When I rejected it the Grail personally cursed me." Explained Kiritsugu.

"I see well that is one powerful curse I don't think even Avalon could heal due to the nature of it being bound to you. It could probably delay it by healing its symptoms but due to the way it is bound unto your very soul I do not believe it could actually remove it. At any rate another thing that must be asked is why I am so different?" Asked Saber.

"You don't appear different." Pointed out Kiritsugu before a thought occurred to him, "How are you still alive, for that matter?"

"Through truly ridiculous amount of luck I was close enough to the grail that I was able to absorb some of the backlash from Excalibur. But far enough away that I only got hit by the shockwave and so was merely sent hurtling from the building. But anyways I was not talking about my appearance I was talking about the fact that I seem to have all of my original Noble Phantasms along with the fact I don't feel nearly as constrained as I was as a servant, if not as powerful as would be as a fully manifested Heroic Spirit." She said as she moved to help Kiritsugu carry the boy out of the destroyed area.

Later after they had dropped the boy off at the hospital Kiritsugu asked, "So what are you going to do from here on out?"

Saber replied, "I don't know maybe I'll travel the world and help out the Church with any monster extermination jobs they might have."

"Ah that's right you are a Christian, what with the quest for the original Holy Grail and all, I guess you would feel a certain desire to aid the church. That boy's family is probably dead I am thinking about adopting him. Still I would like to ask for one favor after I'm dead could you please look after him for me?"

"Fine, though you better not complain if I ever stop by here." She said.

"Heh, Don't worry I won't." Said Kiritsugu.

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Two men wake up finding themselves in a world not of men. One is a hero of legendary standing the other his friend, vassal and a magus. Waking up the magus says, "Rider you're alive."

The man identified as Rider proclaims, "Ha, of course I am alive as if even the King of Heroes could kill me. Though Waver what happened after I got stabbed by Archer?"

"After Archer stabbed you he seemed to realize that Saber had reached the grail and so hurried off before he had a chance to kill after that I tried to heal you and then there was this flash of light and I woke up here." Explained Waver Velvet and then he asked, "But Rider where are we."

"Well if I had to guess I would have to say we are in the lands of the Fae, but don't worry I will protect you." saying that he and the young man named Waver Velvet started to look for a way back home.

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A knight wakes up in a dark room. Though he had died with the destruction of his prison he had been hurled out into the world and beyond. He wakes up beneath an alien sky and in an alien room. He feels his power greater than it was before. He looks up and sees a wizard and though he had been betrayed and crushed still he had his dream and his honor and so with that in mind Diarmud of the Shinning Face simply said, "So you are my master."

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A masked man wakes up in an alley in some city whose name he is not aware and though he does not know it yet he is no longer on his home world. As the man stalks out of the alley his only thoughts are, "The shadows shall rise." Set on his path the 18th generation Hassan-i-Sabah sets out to explore his new surroundings.

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Tonight in a city in an alien world to both two men murder a family. Both exemplify the worst attributes humans can possess. One asks the other, "Hey Mister Bluebeard what happened last thing I remember is this splitting feeling in my skull and then nothing?"

"Ah, my dear Ryonnuske it seems we have been given a second chance tonight we shall rest and tomorrow we shall see about initiating our plans again." Said the one called Bluebeard.

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Contrary to what Hollywood might tell you surviving an explosion is not easy nor is it comfortable. As I am counting my broken ribs I see a couple of the Kemmlerites and their zombie hordes approaching me. Just as I am pretty sure I am about to die a (and I kid you not) knight jumps out of nowhere and picking up some random branch off the ground proceeds to just absolutely butcher them. When the Kemmlerites try to use magic on him it just slides off and you quickly got the idea that they would probably have more affect if they just threw water balloons and hoped his armor rusted.

After his scarily short battle he approaches me and as I get a good look at his armor (which is some sort of Purplish-Black) which has a very gothic feel too it and was definitely designed to be intimidating. I am starting to get worried as he approaches and planning on going out with one last snark when all of a sudden he bows down and says, "I have come my Master."

After that I hear my own little shoulder-devil say, "Oh, you do not know what a wonderful gift you have received my host."

Between the shadow of a fallen angel and the super-powerful there is only one real response, "Hell's Bells, what have I gotten myself into?"

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**A****gain this is my first real story and I (currently) have no beta reader, though I am looking for one and if anyone is interested please PM me, so please go easy on me. **

**Any reviews are welcome, though I ask that any flamers at least keep the obscenities down to a minimum. I will answer any questions that might be asked (so long as they don't reveal anything to important about the plot) either by directly PM the asker or by posting it at the bottom of my next new chapter.**


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